Abstract: A set of data is received containing values associated with respective data points, the values associated with each of the data points being characterized by a distribution. The values for each of the data points are expressed in a form that includes information about a distribution of the values for each of the data points. The distribution information is used in clustering the set of data with at least one other set of data containing values associated with data points.

Abstract: A set of data is received containing values associated with respective data points, the values associated with each of the data points being characterized by a distribution. The values for each of the data points are expressed in a form that includes information about a distribution of the values for each of the data points. The distribution information is used in clustering the set of data with at least one other set of data containing values associated with data points.

Abstract: A genetic deletion mutant live E. coli vaccine suitable for mass application to poultry, including chickens, is provided. Also provided is a safe and effective method to protect poultry against the ravages of Escherichia coli bacillosis infection and disease in which a live mutant aroA-gene deleted E. coli immunogen is administered to chickens, turkeys and the like via mass application routes such as coarse sprays and drinking water.

Abstract: There is provided a vaccine composition comprising a combination of a genetic deletion mutant S. typhimurium microorganism and a genetic deletion mutant E. coli microorganism, suitable for mass application to poultry. Also provided is a safe and effective method to protect poultry against the ravages of E. coli and Salmonella infection and disease.

Abstract: Methods and systems for processing a request of changing a first node having a first service connecting with a second node in a network environment are described herein. In one aspect of the invention, an exemplary method includes dynamically launching a second service at the first node, connecting the second service with the second node, directing requests for service to the second service, and terminating the first service. Other methods and systems are also described.

Abstract: A method, apparatus, and system in which a network system includes a virtual graph composed of a plurality individual networks. A first individual network is associated with a first user. The first individual network includes a plurality of service modules modeled to be representing a first set of network elements. The second individual network is associated with a second user. The second individual network includes a plurality of service modules modeled to be representing a second set of network elements. The second set of network element differs in the type of network elements included in the second individual network and the topological order of the network elements in the second individual network than the first set of network elements.

Abstract: A set of data is received containing values associated with respective data points, the values associated with each of the data points being characterized by a distribution. The values for each of the data points are expressed in a form that includes information about a distribution of the values for each of the data points. The distribution information is used in clustering the set of data with at least one other set of data containing values associated with data points.

Abstract: A domain name server, DNS, for Internet Protocol or Intranet Protocol networks, that has a non-cached domain name server connected to a cached domain name server, and a query server that is connected to both the non-cached DNS and the cached DNS. The query server balances the query load between the DNSs. The query server compares counts of outstanding queries of each DNS and assigns the next query to the DNS with the fewer outstanding counts, unless the query is a special type known as an authoratative query. All authoratative queries are processed by the non-cached DNS. This is because the DNS information stored in the non-cached server is more carefully updated so its information has a higher level of correctness than the information in the cached DNS. Periodic updating of the non-cached DNS keeps its information at this higher level of correctness.

Abstract: A method and system for maintaining a secure association between a client and a server in a distributed computing system by computing a session identifier as a function of a Kerberos-based authentication ticket. The session identifier is independently derived or verified by the client and the server upon a first request by the client to the server, and each subsequent request by the client to the server is tagged with this session identifier to provide a reliable security association.

Abstract: A power amplifier includes a plurality of signal amplifying stages. An amplitude compensator positioned prior to the ultimate signal amplifying stage equalizes the signal amplitudes in the frequency band of interest to provide a substantially flat frequency response. Fail-soft operation is established by providing switchably redundant amplifiers. When an operating amplifier is detected as failing, automatic switching is performed to replace the failing unit with an identical unit to maintain amplifier operation. High-power amplification is accomplished by splitting a preamplified signal into a plurality of signals, amplifying the lower level signals so obtained, and then recombining the amplified signals.

Abstract: In an amplifier for amplifying a pulsed sinusoidal carrier signal, wherein the amplifier employs an amplifier element operative as Class-C with a saturation operation region which increases the sharpness of leading and trailing edges of a rectangular pulse envelope of the pulsed carrier signal for undesirable spectral spreading of energy of the signal, a method of reducing the spectral spreading of the energy employs a modification of the rectangular envelope of the pulsed carrier signal to a trapezoidal envelope. The leading and the trailing edges of the trapezoidal envelope constitute envelopes of sinusoidal waveforms of increasing and decreasing amplitude, respectively. The peak amplitudes of the largest amplitude sinusoidal of the leading and the trailing edges have powers which exceed a power level inducing the saturated operation of the amplifier element such that there is a decrement in incremental power gain by a factor of approximately 3 dB.

Abstract: A solid state amplifier for a microwave transmitter includes a power divider wherein a signal to be amplified is divided into signals of equal signal levels. The equal level signals are respectively coupled to a plurality of amplifiers wherefrom the amplified signals are coupled to a combiner wherein the amplified signals are added and signal sum provided at an output terminal of the combiner. Each of the amplifiers may be comprised of a first stage amplifier, the output signal of which is coupled to a multiplicity of component amplifiers which, in tern, are coupled to a the output terminal of the first stage amplifier via a second power divider wherefrom signals of equal level are provided to the component amplifiers. Bias voltages are provided to the amplifiers via a modularized power supply having some modules with redundant converters.

Abstract: Broadband, monolithic, planar m.times.m and m.times.n transfer switches with diode switching elements are disclosed. Symmetry of the switches maintain equal insertion amplitude and phase performance. Compensation of phase unbalance caused by diode parasitic capacitance is provided by inductors serially coupled between the diodes and the input and output terminals of the transfer switch. Stripline transmission lines are utilized and isolation between the transmission lines is provide in regions of stripline cross over in the plane.

Abstract: There is described a 2.times.2 switch matrix which includes four 1.times.1 switch matrix modules. Each 1.times.1 switch matrix module consists of an active power divider switch (APDS), an active power combiner switch (APCS) and an air bridge crossover. Additional APDSs and APCSs are utilized in the matrix to compensate for path length differences between different input to output signal paths thus providing good phase and amplitude tracking. The basic switch matrix modules are utilized to form a 2.times.2 switch matrix whereby two primary input ports can be connected to any one of two primary output ports. The 2.times.2 switch matrix is utilized to formulate larger matrix arrays as N.times.M configuration. Each of the active power divider switches and power combiner switches utilize two separate dual gate FETs which are suitably interconnected, depending upon whether the circuit is to be used as a power combiner or power divider.

Abstract: A monolithic double balanced mixer with a high third order intercept point employs a local oscillator signal which is applied to the input port of a first active distributed element balun. The balun has two outputs which are applied via amplifiers to respective inputs of a double balanced resistive FET quad mixer. The double balanced resistive FET quad mixer employs four MESFETs arranged in a ring configuration. Two additional inputs to the quad mixer are obtained from a second balun which is also of an active distributed element configuration and receives at the input the RF signal. The quad mixer operates to produce mixing of the LO and RF signals at the outputs thereof. The outputs of the quad mixer are applied to a combiner which operates to combine the outputs of the quad mixer to produce at the combiner output an IF signal. The combiner can be a common gate combiner configuration with active loads or a distributed configuration employing FET devices in a distributed transmission line type of circuit.

Abstract: A digitally controlled active phase shifter with vernier control consists of a 180 degree phase bit in series with a 90 degree bit and a digitally controlled active vector generator with vernier control. The digitally controlled active vector generator consists of an active power divider with digitally adjustable amplitude, a pair of phase delay networks with an active power combiner employing vernier control. The power divider consists of two sets of parallel pairs of FET's in cascode configuration with all input nodes connected together and all output nodes from the same set tied together. The FET at the output node of each pair is a common gate configuration with its gate RF grounded through a bypass capacitor. The gate bias voltage is applied to the common gate FET to switch it ON or OFF to thereby provide a set of desired signal amplitudes which can be obtained by selecting the gain of each of the cascode stages in each of the parallel pairs.

Abstract: Amplifiers operating in push-pull are implemented to obviate input baluns and output signal combiners and their attendant losses. Amplifiers having two signal branches that each receive the input signal and have their signal branch outputs connected directly together. Each branch operates during alternate half cycles of the input signal while direct combining of the branch signal outputs produces a composite signal corresponding to the complete input signal. Each branch includes a matching input circuit and a heterojunction bipolar transistor whcih may be configured in either common collector or common emitter arrangement. The transistors are different since one is an NPN while the other is a PNP but they are selected to have similar direct current and radio frequency characteristics.

Abstract: A microwave planar switch matrix for selectively connecting various ones of M inputs to N outputs. The switch matrix includes a semi-insulative substrate on one side of which are conductors arranged in rows and columns, the interconnection of the rows and columns forming the intersections of the matrix, a plurality M.multidot.N of two-way active power dividers arranged in the rows near each intersection, respectively, and a plurality M.multidot.N of two-way power combiners arranged in the columns near the intersections, respectively, and M.multidot.N switches selectively connecting respectively one output of the power dividers to one input of the power combiners. Because the power dividers and power combiners utilize active components, net power gain through the matrix is possible. Air bridges separate the row and column conductors at the intersections.

Abstract: An in-phase power divider is constructed of a double field-effect transistor having a common source, first and second gates and first and second drains. The gates are coupled together and adapted to receive a radio frequency signal of power P to be power divided. The power divided output signals each at substantially P.div.2 or more appear at the drains. An alternative power divider for producing unequal power division is constructed of a double dual gate FET having, in addition to the above-mentioned elements, third and fourth gates. By appropriate unequal application of gate bias to the additional gates unequal power division is effected.

Abstract: An in-phase power combiner is constructed of a double field-effect transistor having a common drain, first and second gates and first and second sources. The gates are adapted to receive radio frequency signals of powers P1and P2, where P1=P2, to be power combined. The combined power output signal P equal to at least P1+P2 appears at the drain. An alternative power combiner for producing power combination of two unequal power input signals is constructed of a double dual gate FET having, in addition to the above-mentioned elements, third and fourth gates.